Casualties unknown

Landing Gear Collapse After Touchdown Leads to Evacuation (N72822)

Denver, CO, US

On April 27, 1993, a Mcdonnell Douglas DC-9-82 (registration N72822) was involved in an aviation accident near Denver, CO. Investigators recorded the probable cause as: Failure of the threads on the right main landing gear apex bolt, causing the gear to rotate 90 degrees and subsequently collapse from overload. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

After touchdown, a landing gear vibration caused the right main gear to collapse. The wing contacted the runway, the aircraft skidded, and two passengers sustained minor injuries during evacuation.

Event Description

Following touchdown, a vibration in the landing gear developed. This vibration led to the collapse of the right main landing gear at a speed of 117 knots. The right wing subsequently contacted the runway surface, and the airplane skidded to a stop on the runway before entering the overrun area. During the ensuing emergency evacuation, two passengers sustained minor injuries.

Examination Findings

Examination of the applicable components did not identify a specific cause for the initial vibration that precipitated the gear collapse. However, the threads on the right main landing gear apex bolt were found to have failed. This failure resulted in a 90-degree rotation of the gear assembly, which then collapsed due to overload. Additionally, the ground spoilers did not deploy during the event. The flight crew reported that they had armed the auto spoiler system.

Previous Incidents

The aircraft manufacturer reported a total of three similar non-flight-test occurrences. In all three of those events, the ground spoilers also failed to extend.

Probable cause

Failure of the threads on the right main landing gear apex bolt, causing the gear to rotate 90 degrees and subsequently collapse from overload.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X12114. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.